The recent measles outbreak in Minnesota has been a sobering reminder of how highly concentrated populations of vaccination skeptics can elevate an entire community’s risk of infection. Around the edges of every headline-grabbing outbreak, there’s a vast range of opinions being circulated about the risks and benefits of early childhood immunization. The vaccination debate maintains a constant presence on social media platforms. These varied viewpoints caught the attention of scientists who are conducting a three-year study on the ways online interactions influence our beliefs.